package solution;

/**
 * 1089. 复写零
 * https://leetcode.cn/problems/duplicate-zeros/description/
 */
class Solution {
    public void duplicateZeros(int[] arr) {
        int cur = 0, dest = -1;
        int n = arr.length;
        while(cur < n) {
            if(arr[cur] == 0) {
                dest += 2;
            } else {
                dest += 1; 
            }
            if(dest >= n - 1) break;
            cur++;
        }
        //处理边界情况
        if(dest == n) {
            arr[n - 1] = 0;
            dest -= 2;
        }
        while(cur >= 0) {
            if(arr[cur] != 0) {
                arr[dest--] = arr[cur--];
            } else {
                arr[dest--] = 0;
                arr[dest--] = 0;
                cur--;
            }
        }
    }
}